JP4897019B2 - Heat treatment device - Google Patents

Description

  The present invention relates to a heat treatment apparatus for heat-treating a substrate.

  In the photolithography process in the manufacturing process of a semiconductor device, for example, resist, BARC (Bottom Anti-Reflective Coating) applied on the surface of a semiconductor substrate (hereinafter, the semiconductor substrate is simply referred to as “wafer” or “substrate”), Heat treatment (pre-baking) to evaporate the solvent contained in various chemicals such as SOG (Spin On Glass), and heat treatment (post-exposure) to promote the chemical reaction of the resist film on the wafer after pattern exposure Various heat treatments such as baking and post-development heat treatment (post-baking) are performed.

  The heat treatment described above is usually performed by placing a wafer on a heat plate maintained at a desired heat treatment temperature in a heat treatment apparatus such as an oven equipped with a heat plate.

  In such a heat treatment apparatus, in order to exhaust the evaporated solvent, the atmosphere in the processing container may be exhausted by connecting to an exhaust system in the factory via an exhaust duct.

  However, in the various chemicals applied to the wafer surface, there are components that are vaporized (sublimated) from the wafer surface at the heat treatment temperature and exhausted as a gas. Some chemical components exhausted as gas are cooled and solidified (sublimated) in the middle of the exhaust flow path such as an exhaust duct exhausted to the exhaust system, and adhere to the inside of the exhaust flow path piping There is. If deposits that accumulate inside the exhaust passage accumulate, the inside of the exhaust passage piping becomes clogged, making it impossible to ensure the required exhaust flow rate. For this reason, there is a case where an exhaust flow rate for exhausting the atmosphere in the processing container of the heat treatment apparatus is detected, or a maintenance process for cleaning and removing deposits adhering to the inside of the exhaust passage pipe.

  For example, as a chemical liquid application device that detects an exhaust flow rate for exhausting the heat treatment unit, an exhaust wind speed sensor that feedback-controls an exhaust air speed of the chemical liquid application processing unit, and an exhaust pipe system for correcting the sensitivity of the exhaust air speed sensor A chemical solution coating apparatus is disclosed (for example, see Patent Document 1).

  Further, for example, in an exhaust system used in an apparatus for semiconductor processing, the upstream portion of the exhaust duct connected to the semiconductor process apparatus is heated to prevent chemical crystals from adhering to the exhaust duct. An exhaust system comprising: heating means; and cleaning means for ejecting liquid into the exhaust duct so as to clean the exhaust duct by removing chemical crystals adhering to the exhaust duct cooled by the cooling means. It is disclosed (for example, see Patent Document 2).

JP-A-4-184914 JP-A-8-107097

  However, in the above-described heat treatment apparatus, when the exhaust flow rate for exhausting the atmosphere in the processing container is detected, or a maintenance process is performed to remove the deposits adhering to the inside of the piping of the exhaust flow path and to clean the inside of the piping. If you have the following problems:

  In the heat treatment apparatus, a flow meter for detecting the exhaust flow rate may be provided on the exhaust flow path. As a flow meter, there is a case where a portion having a narrowed flow path is provided in the middle of the exhaust flow path, and a flow rate is determined by measuring a differential pressure before and after that portion. The portion where the flow path is narrowed is likely to be clogged earlier than other portions, and may become a so-called clogged portion. At this time, if even a part of the exhaust flow path is clogged, it may not be possible to secure an exhaust flow rate for exhausting the atmosphere in the processing container. Therefore, even if only the part where the flow path is narrowed is clogged, the operation of the heat treatment device is stopped, the adhering matter adhering to the inside of the pipe of the exhaust flow path is removed, and the maintenance process is performed to clean the inside of the pipe And the maintenance cycle may be shortened.

  When operating such a heat treatment apparatus, the user may determine a maintenance cycle according to the purpose of use. However, there is a trade-off between increasing the maintenance cycle and performing cleaning in response to the actual occurrence of a clogged portion. For example, when increasing the fluctuation allowable range of the exhaust flow rate, a periodic maintenance process cycle is predicted, and a clogged portion may be cleaned at each predicted cycle. In this case, although the maintenance cycle can be made relatively long, the maintenance process may not be performed in response to the actual occurrence of a clogged portion. On the other hand, when the allowable range of fluctuation of the exhaust flow rate is reduced, the value of the exhaust flow rate may be monitored and the clogged portion may be cleaned every time the clogged portion is generated in the exhaust duct. In this case, although the maintenance process can be performed in response to the actual occurrence of the clogged portion, the maintenance cycle may be shortened.

  Furthermore, when the type of chemical solution used is changed and the sublimation component of the chemical solution is changed, the frequency of occurrence of clogged portions may vary, but the maintenance cycle may be determined according to the chemical solution. It can be difficult. In such a case, maintenance is performed in accordance with a cycle set shorter than a really necessary cycle, so that the maintenance management cost may increase.

  The present invention has been made in view of the above points, and even when the allowable range of fluctuation of the exhaust flow rate is set small, the maintenance cycle can be lengthened, and the exhaust flow rate is stabilized and the maintenance management cost is reduced. Provided is a heat treatment apparatus capable of performing the above.

  In order to solve the above-described problems, the present invention is characterized by the following measures.

  The present invention relates to a heat treatment apparatus in which a substrate having a coating film formed on the surface of the substrate is placed on a hot plate and subjected to heat treatment, a treatment container storing the hot plate, the treatment vessel, and the treatment vessel An exhaust passage that connects an exhaust system that exhausts the atmosphere of the atmosphere, an air introduction passage that introduces air into the exhaust passage through an introduction port provided in the middle of the exhaust passage, and the introduction of the atmosphere And a flow meter provided on the road, and the exhaust flow rate from the inside of the processing vessel is estimated by measuring the exhaust flow rate in the atmosphere introduction path.

  According to the present invention, in the heat treatment apparatus, the maintenance cycle can be lengthened even when the allowable range of fluctuation of the exhaust flow rate is set small, and the exhaust flow rate can be stabilized and the maintenance management cost can be reduced. .

1 is a schematic plan view showing a resist coating and developing treatment system including a heat treatment apparatus according to a first embodiment. 1 is a schematic front view of a resist coating and developing treatment system including a heat treatment apparatus according to a first embodiment. 1 is a schematic rear view of a resist coating and developing treatment system including a heat treatment apparatus according to a first embodiment. It is a schematic sectional drawing which shows the exhaust system of the heat processing apparatus which concerns on 1st Embodiment. It is a schematic front view which shows the heat processing apparatus which concerns on 1st Embodiment. It is a flowchart for demonstrating the procedure of each process of the monitoring method of the exhaust gas flow rate in the heat processing apparatus which concerns on 1st Embodiment. The figure which shows typically a mode that the deposit | attachment gradually adheres in the exhaust flow path and the exhaust gas flow rate from the inside of the processing container decreases as the operation of the heat treatment apparatus according to the first embodiment continues (part 2). 1). The figure which shows typically a mode that the deposit | attachment gradually adheres in the exhaust flow path and the exhaust gas flow rate from the inside of the processing container decreases as the operation of the heat treatment apparatus according to the first embodiment continues (part 2). 2). The figure which shows typically a mode that the deposit | attachment gradually adheres in the exhaust flow path and the exhaust gas flow rate from the inside of the processing container decreases as the operation of the heat treatment apparatus according to the first embodiment continues (part 2). 3). As a comparative example, a schematic diagram showing a state in which deposits gradually adhere to the exhaust flow path and the exhaust flow rate from the processing container decreases as the operation of the heat treatment apparatus in which the flow meter is provided on the exhaust flow path continues. (No. 1) shown in FIG. As a comparative example, a schematic diagram showing a state in which deposits gradually adhere to the exhaust flow path and the exhaust flow rate from the processing container decreases as the operation of the heat treatment apparatus in which the flow meter is provided on the exhaust flow path continues. (2) shown in FIG. It is a schematic front view which shows the heat processing apparatus which concerns on 2nd Embodiment. It is a flowchart for demonstrating the procedure of each process of the maintenance process of the heat processing apparatus which concerns on 2nd Embodiment. It is a schematic front view which shows the heat processing apparatus which concerns on the 1st modification of 2nd Embodiment. It is a schematic front view which shows the heat processing apparatus which concerns on the 2nd modification of 2nd Embodiment.

Next, a mode for carrying out the present invention will be described with reference to the drawings.
(First embodiment)
First, the heat treatment apparatus according to the first embodiment will be described with reference to FIGS. 1 to 11.

  First, the case where the heat treatment apparatus according to the present embodiment is applied to the heat treatment apparatus in the resist coating and developing treatment system will be described.

  FIG. 1 is a schematic plan view showing a resist coating and developing treatment system including a heat treatment apparatus according to the present embodiment, FIG. 2 is a schematic front view of the resist coating and developing processing system, and FIG. 3 is a resist coating and developing processing system. FIG.

  As shown in FIG. 1, the resist coating / developing processing system 1 carries, for example, 25 wafers W in the cassette unit from the outside to the resist coating / developing processing system 1 and also loads the wafers W into the cassette C. A cassette station 2 that carries in and out, a processing station 3 that is provided adjacent to the cassette station 2 and that has a multistage arrangement of various processing units that perform predetermined processing in a single-wafer type in the coating and developing process, and this processing The interface unit 4 that transfers the wafer W to and from an exposure apparatus (not shown) provided adjacent to the station 3 is integrally connected.

  The cassette station 2 can mount a plurality of cassettes C at a predetermined position on the cassette mounting table 5 in a row in the horizontal X direction. Further, the cassette station 2 is provided with a wafer transfer arm 7 that can move along the X direction on the transfer path 6. The wafer transfer arm 7 is also movable in the wafer arrangement direction (Z direction; vertical direction) of the wafers W accommodated in the cassette C, and is selective to the wafers W in each cassette C arranged in the X direction. Is configured to be accessible.

  Further, the wafer transfer arm 7 is configured to be rotatable in the θ direction about the Z axis, and as described later, with respect to the transition device (TRS) 31 belonging to the third processing unit group G3 on the processing station 3 side. Even it is configured to be accessible.

  The processing station 3 includes, for example, five processing unit groups G1 to G5 in which a plurality of processing units are arranged in multiple stages. As shown in FIG. 1, on the front side of the processing station 3, a first processing unit group G1 and a second processing unit group G2 are arranged in this order from the cassette station 2 side. In addition, on the back side of the processing station 3, a third processing unit group G3, a fourth processing unit group G4, and a fifth processing unit group G5 are arranged in order from the cassette station 2 side. A first transport mechanism 110 is provided between the third processing unit group G3 and the fourth processing unit group G4. The first transfer mechanism 110 is configured to selectively access the first processing unit group G1, the third processing unit group G3, and the fourth processing unit group G4 to transfer the wafer W. A second transport mechanism 120 is provided between the fourth processing unit group G4 and the fifth processing unit group G5. The second transport mechanism 120 is configured to selectively access the second processing unit group G2, the fourth processing unit group G4, and the fifth processing unit group G5 to transport the wafer W.

  In the first processing unit group G1, as shown in FIG. 2, a liquid processing unit for supplying a predetermined processing liquid to the wafer W to perform processing, for example, a resist coating unit (COT) for applying a resist liquid to the wafer W 10, 11, 12, and bottom coating units (BARC) 13 and 14 for forming an antireflection film for preventing reflection of light during exposure are stacked in five stages in order from the bottom. In the second processing unit group G2, liquid processing units, for example, development processing units (DEV) 20 to 24 that perform development processing on the wafer W are stacked in five stages in order from the bottom. Further, at the bottom of the first processing unit group G1 and the second processing unit group G2, a chemical chamber (CHM) for supplying various processing liquids to the liquid processing units in the processing unit groups G1 and G2. 25 and 26 are provided, respectively.

  On the other hand, in the third processing unit group G3, as shown in FIG. 3, the temperature adjustment unit (TCP) 30, the transition device (TRS) 31 for transferring the wafer W, and the highly accurate temperature are sequentially arranged from the bottom. Heat treatment units (ULHP) 32 to 38 that heat-treat the wafer W under management are stacked in nine stages.

  In the fourth processing unit group G4, for example, a high-precision temperature control unit (CPL) 40, pre-baking units (PAB) 41 to 44 that heat-treat the resist-coated wafer W, and a wafer W that has been developed are heat-treated. Post baking units (POST) 45 to 49 are stacked in 10 stages in order from the bottom.

  In the fifth processing unit group G5, a plurality of heat treatment units that heat-treat the wafer W, for example, high-precision temperature control units (CPL) 50 to 53, post-exposure baking units (PEB) 54 to heat-treat the exposed wafer W, 59 are stacked in 10 steps from the bottom.

  A plurality of processing units are arranged on the positive side in the X direction of the first transfer mechanism 110 as shown in FIG. 1, for example, to hydrophobize the wafer W as shown in FIG. Adhesion units (AD) 60 and 61 and heating units (HP) 62 and 63 for heating the wafer W are stacked in four stages in order from the bottom. Further, as shown in FIG. 1, for example, a peripheral exposure unit (WEE) 64 that selectively exposes only the edge portion of the wafer W is disposed on the back side of the second transport mechanism 120.

  As shown in FIG. 1, the interface unit 4 includes a first interface unit 100 and a second interface unit 101 in order from the processing station 3 side. In the first interface unit 100, a wafer transfer arm 102 is disposed at a position corresponding to the fifth processing unit group G5. On both sides of the wafer transfer arm 102 in the X direction, for example, buffer cassettes 103 (the back side in FIG. 1) and 104 (the front side in FIG. 1) are respectively installed. The wafer transfer arm 102 can access the heat treatment apparatus and the buffer cassettes 103 and 104 in the fifth processing unit group G5. The second interface unit 101 is provided with a wafer transfer arm 106 that moves on a transfer path 105 provided in the X direction. The wafer transfer arm 106 is movable in the Z direction and rotatable in the θ direction, and can access the buffer cassette 104 and an exposure apparatus (not shown) adjacent to the second interface unit 101. . Therefore, the wafer W in the processing station 3 can be transferred to the exposure apparatus via the wafer transfer arm 102, the buffer cassette 104, and the wafer transfer arm 106, and the wafer W after the exposure processing is transferred to the wafer transfer arm 106 and the buffer. It can be transferred into the processing station 3 via the cassette 104 and the wafer transfer arm 102.

  Next, the exhaust system of the heat treatment apparatus will be described with reference to FIG. FIG. 4 is a schematic cross-sectional view showing an exhaust system of the heat treatment apparatus according to the present embodiment. Here, as an example, a heat treatment apparatus in the heat treatment apparatuses 54 to 59 which is a post-exposure baking unit (PEB) included in the fifth treatment unit group G5 will be described.

  As shown in FIG. 4, the heat treatment apparatuses 54 to 59 each have a casing 67 that can be closed. The casing 67 accommodates a hot plate 70 and a cooling plate 71 which are heat treatment apparatuses described later. In addition, main exhaust ports 65 are provided in the vicinity of the rear end of the fifth processing unit group G5. A processing container 70b that houses a heat plate 70, which will be described later, which is a heat treatment device in the heat treatment apparatuses 54 to 59, is connected to the main exhaust port 65 by an exhaust passage 72, which will be described later. In addition to the exhaust flow path 72, the interior of the housing 67 of the heat treatment devices 54 to 59 may also be connected to the main exhaust port 65 through an exhaust flow path (not shown). Further, as shown in FIG. 4, the main exhaust port 65 communicates with an exhaust duct 66 connected to an exhaust system (for example, a factory exhaust system). Therefore, the atmosphere in the heat treatment apparatus in each of the heat treatment apparatuses 54 to 59 is exhausted by the factory exhaust system via the exhaust passage 72, the main exhaust port 65, and the exhaust duct 66.

  Next, the heat treatment apparatus will be described with reference to FIG. FIG. 5 is a schematic front view showing the heat treatment apparatus according to the present embodiment.

  The heat treatment apparatus includes a hot plate 70, a treatment container 70 b, an exhaust passage 72, an air introduction passage 73, a flow meter 74, and a monitoring unit 75. The heat treatment apparatus heats a substrate having a coating film formed on the surface of the substrate.

  The hot plate 70 places a wafer W coated with chemicals such as resist, BARC, SOG, etc., and heats it to a predetermined temperature, for example, 130 ° C. As shown in FIG. 5, the hot plate 70 is, for example, a lid 70 a that can move up and down, and is positioned below the lid 70 a and is integrated with the hot plate 70 a to cooperate with the hot plate 70 b. A support ring 70c is provided.

  The support ring 70c has, for example, a substantially cylindrical shape whose upper and lower surfaces are open, and the heat plate 70 is accommodated inside the support ring 70c. The hot plate 70 has, for example, a thick disk shape, and a heater 70d is built in the hot plate 70, for example. The heating plate 70 can be heated to a predetermined heating temperature, for example, 130 ° C. by the heater 70d.

  Near the center of the hot plate 70, a plurality of, for example, three through holes 70e are provided. Each through hole 70e is formed with a support pin 70g that can be lifted and lowered by a lifting drive mechanism 70f. With the support pins 70g, the wafer W can be moved up and down on the hot plate 70, and the wafer W can be transferred between the hot plate 70 and the cooling plate 71 shown in FIG.

The lid 70a has a substantially cylindrical shape with an open bottom surface. An opening 70h is provided in the center of the upper surface of the lid 70a, and an exhaust passage 72 that connects the processing container 70b and the exhaust system is connected to the opening 70h. Further, the lid 70a is provided with a gas supply port (not shown), and an inert gas such as nitrogen (N ₂ ) gas is introduced from the gas supply port (not shown), and N ₂ is directed onto the hot plate 70 toward the wafer W. The gas may be discharged radially. Thus, by discharging N ₂ gas radially, adhesion to the wafer W due to diffusion of a catalyst or the like generated by heating can be prevented.

  The lid 70a is supported by an arm that can be raised and lowered (not shown), and moves up and down at a predetermined timing to form a processing container 70b integrally with the support ring 70c, or to open the processing container 70b. It is configured to be able to.

  The exhaust flow path 72 connects the processing container 70b and an exhaust system (factory exhaust system) that exhausts the atmosphere in the processing container 70b. Specifically, the opening 70h formed in the lid 70a of the processing container 70b is provided to connect the exhaust system. The exhaust passage 72 connected to the opening 70h is connected to the exhaust duct 66 at the main exhaust port 65 in the same manner as the exhaust passage 72 of each apparatus included in the resist coating and developing treatment system 1 described above with reference to FIG. The An introduction port 76 is provided in the middle of the exhaust channel 72 that connects the opening 70 h of the processing container 70 b and the exhaust duct 66, and the atmosphere is introduced into the exhaust channel 72 from the outside via the introduction port 76. An air introduction path 73 to be introduced is provided. One end of the air introduction path 73 is an air intake port 77 from the atmosphere, and the other end is an introduction port 76 of the exhaust flow path 72.

  As described above, each chemical solution such as resist, BARC, and SOG is applied to the wafer W to be heat-treated by the hot plate 70. When the wafer W is heat-treated, the components contained in each chemical solution are vaporized (sublimated) and exhausted from the processing container 70b through the exhaust flow path 72 by the exhaust system.

  The exhaust system according to the present embodiment corresponds to a factory exhaust system provided outside the resist coating and developing treatment system 1. However, the exhaust system may be provided independently in the resist coating and developing treatment system 1. Further, it may be provided independently in correspondence with the heat treatment apparatus inside or outside the resist coating and developing treatment system 1.

  A flow meter 74 is provided on the air introduction path 73. The flow meter 74 measures an exhaust flow rate (Q2 to be described later) exhausted from the air introduction path 73 toward the introduction port 76 provided in the exhaust flow path 72 from the air intake port 77. The flow meter 74 is not particularly limited. For example, a throttle flow meter (Venturi meter) or a differential pressure type flow meter (orifice flow meter) can be used. When a throttle flow meter (venturi meter) is used, as shown in FIG. 5, the diameter of the air introduction path 73 is narrowed in the middle, and the narrower diameter portion of the air intake port 77 side and the exhaust flow path 72 The pressure difference with the inlet 76 side is measured. Further, when a differential pressure type flow meter (orifice flow meter) is used, a plate-like orifice (throttle mechanism) is provided in the middle of the air introduction path 73, and the introduction of the orifice into the atmosphere intake 77 side and the exhaust flow path 72 is provided. The pressure difference with the mouth 76 side is measured.

  However, the method of the flow meter is not limited to the restriction flow meter (Venturi meter) or the differential pressure type flow meter (orifice flow meter). In addition, a float type flow meter, laminar flow type flow meter, hot wire type flow meter Various flow meters such as a Karman vortex flow meter, a turbine flow meter, and an ultrasonic flow meter can be used.

  The exhaust flow path 72 to which the air introduction path 73 is connected via the introduction port 76 is connected to the exhaust duct 66 in the resist coating and developing treatment system 1. Further, the exhaust duct 66 of the coating and developing treatment system 1 is connected to a factory exhaust system and is exhausted by an exhaust device (not shown) included in the factory exhaust system. Note that a region surrounded by a dotted line I is defined as a heat treatment apparatus according to the present invention.

  Here, let QT be an exhaust flow rate at which the factory exhaust system exhausts the exhaust duct 66 of the resist coating and developing treatment system 1. Further, the exhaust flow rate 72 for exhausting the exhaust flow path 72 in the vicinity of the main exhaust port 65 by the exhaust flow path 72 of the heat treatment apparatus connected to the main exhaust port 65 of the exhaust duct 66 of the resist coating and developing processing system 1 is Q0. Further, the exhaust flow rate of the exhaust flow path 72 between the introduction port 76 where the exhaust flow path 72 is connected to the air introduction path 73 and the processing vessel 70b, that is, the exhaust flow rate exhausted from the processing vessel 70b by the exhaust system is defined as Q1. . Further, an exhaust flow rate of the air introduction path 73 between the introduction port 76 where the exhaust flow path 72 is connected to the air introduction path 73 and the air intake port 77, that is, an exhaust flow rate at which the exhaust system exhausts the air introduction path 73 is denoted by Q2. To do. Then, Q0 = Q1 + Q2 and Q0 <QT. Here, the exhaust capacity of the factory exhaust system, the duct diameter of the exhaust duct 66 of the resist coating and developing system 1, the diameter with the exhaust passage 72 of the heat processing apparatus and other various apparatuses in the resist coating and developing system 1, respectively. Q0 << QT can be achieved by adjusting the opening of an exhaust flow rate adjustment damper (not shown) provided in the middle of the exhaust flow path 72 of the engine. In this case, the sum Q0 of Q1 and Q2 can be made substantially constant without depending much on the state of other devices in the resist coating and developing system 1.

  The monitoring unit 75 includes a monitoring unit main body 75a and an alarm output unit 75b. The monitoring unit 75 monitors the exhaust flow rate from the inside of the processing container 70b based on the exhaust flow rate Q2 of the air introduction path 73. The monitoring unit 75 may have a function of estimating the exhaust flow rate Q1 from the processing container 70b by the flow meter 74 measuring the exhaust flow rate Q2 of the atmosphere introduction path 73. In this case, Q1 can be estimated by subtracting Q2 from Q0.

  Next, with reference to FIG. 6, a method for monitoring the exhaust gas flow rate with a flow meter during operation of the heat treatment apparatus will be described. FIG. 6 is a flowchart for explaining the procedure of each step of the exhaust gas flow rate monitoring method in the heat treatment apparatus according to the present embodiment.

  The exhaust gas flow rate monitoring method according to the present embodiment includes a step of measuring Q2 (step S11), a step of sending Q2 to the monitoring unit 75 (step S12), and a step of estimating Q1 by subtracting Q2 from Q0 (step S12). S13), a step of determining whether Q2 is larger than the upper reference value (step S14), and a step of outputting an alarm (step S15).

  After starting the operation of the heat treatment apparatus, first, step S11 is performed. In step S <b> 11, the exhaust flow rate of the air introduction path 73 is measured by the flow meter 74.

  Next, step S12 is performed. In step S <b> 12, the measured value of the measured exhaust flow rate Q <b> 2 of the air introduction path 73 is sent to the monitoring unit 75.

  Next, step S13 is performed. In step S13, the sum Q0 (= Q1 + Q2) of the exhaust flow rate Q1 from the inside of the processing vessel 70b and the exhaust flow rate Q2 of the atmosphere introduction path 73 is made substantially constant by the method described above, for example, from Q0 to Q2. By subtracting the measured value, Q1 is calculated and Q1 is estimated.

  Next, step S14 is performed. In step S14, an upper limit reference value QALM for Q2 is determined in advance, and a magnitude relationship between the predetermined upper limit reference value QALM and the measured value of Q2 is determined. Specifically, it is determined whether Q2 is larger than QALM. If Q2 is smaller than QALM, the process returns to step S11, and the processes from step S11 to step S14 are repeated. On the other hand, if Q2 is greater than QALM, the process proceeds to step S15.

  In step S14, the lower limit reference value QALM 'of Q1 may be determined in advance, and the magnitude relationship between the predetermined lower limit reference value QALM' and the estimated value of Q1 may be determined. In this case, specifically, it is determined whether Q1 is smaller than QALM '. If Q1 is larger than QALM', the process returns to step S11 again. On the other hand, if Q1 is smaller than QALM ', the process proceeds to step S15.

  In step 15, if Q2 is larger than QALM, or if Q1 is smaller than QALM ', the exhaust flow rate Q1 from the inside of the processing container 70b has decreased, so an alarm is output. The alarm output unit 75b of the monitoring unit 75 outputs an alarm, stops the operation of the heat treatment apparatus, and proceeds to the maintenance process. In the maintenance process, deposits attached to the exhaust flow path 72 are removed, and the exhaust flow path 72 is cleaned. After cleaning of the exhaust passage 72 is completed, the operation of the heat treatment apparatus is resumed.

  Next, referring to FIGS. 7 to 11, in the heat treatment apparatus according to the present embodiment, the maintenance cycle can be lengthened even when the allowable range of fluctuation of the exhaust flow rate is set small, and the exhaust flow rate is stabilized. Explain what can be done.

  FIGS. 7 to 9 are schematic views showing that deposits gradually adhere to the exhaust flow path and the exhaust flow rate from the processing container decreases as the operation of the heat treatment apparatus according to the present embodiment continues. FIG. FIG. 10 and FIG. 11 show that, as a comparative example, with the continuation of the operation of the heat treatment apparatus in which a flow meter is provided on the exhaust passage, deposits gradually adhere to the exhaust passage and the exhaust flow rate from the inside of the processing vessel decreases. It is a figure which shows typically the state to do.

  FIG. 7 shows a state in which the exhaust flow path 72 has not been operated after the maintenance process of the exhaust flow path 72 and the deposit 78 is hardly adhered in the exhaust flow path 72. At this time, Q1 is QN1, and Q2 is QN2. QN1 is a value near the maximum within the variation allowable range of Q1. QN2 is a value in the vicinity of the minimum in the variation allowable range of Q2. At this time, the value of Q2 sent from the flow meter 74 to the monitoring unit 75 is QN2, and since QN2 <QALM (QN1> QALM ′), the monitoring unit 75 does not output an alarm.

  FIG. 8 shows a state in which the deposit 78 is slightly adhered in the exhaust flow path 72 after performing the maintenance process and performing a little operation as compared with FIG. 7. At this time, Q1 is QS1, and Q2 is QS2. QS1 is a value near the center in the variation allowable range of Q1. QS2 is a value near the center in the variation allowable range of Q2. Although it depends on the temperature of the inner wall of the pipe, it adheres to the exhaust passage 72 between the processing vessel 70b and the inlet 76 where the air introduction path 73 is connected to the exhaust passage 72, and the exhaust is attached to the exhaust side of the processing vessel 70b. It does not adhere as much as the system side. Also at this time, since the value of Q2 sent from the flow meter 74 to the monitoring unit 75 is QS2 and QS2 <QALM (QS1> QALM ′), the monitoring unit 75 does not output an alarm. Further, since the exhaust from the processing container 70b does not flow into the air introduction path 73 and the flow meter 74, the attached matter does not adhere. In addition, in the introduction port 76, the atmosphere from the atmosphere intake port 77 flows into the exhaust passage 72 through the atmosphere introduction path 73. Accordingly, air from the atmosphere is constantly blown to the exhaust flow path 72 in the vicinity of the introduction port 76, and therefore, deposits including sublimates do not adhere. Furthermore, since the air from the above-described air introduction path 73 flows into the exhaust flow path 72 on the exhaust system side of the introduction port 76 together with the exhaust from the processing container 70b, the adhering matter does not adhere.

  FIG. 9 shows a state in which a large amount of deposit 78 is adhered in the exhaust flow path 72 after further operation as compared with FIG. 8. At this time, Q1 is QA1 and Q2 is QA2. QA1 is a value in the vicinity of the minimum in the fluctuation allowable range of Q1. QA2 is a value near the maximum within the variation allowable range of Q2. At this time, the value of Q2 sent from the flow meter 74 to the monitoring unit 75 is QA2, and QA2> QALM (QA1 <QALM ′), so that the monitoring unit 75 reduces the exhaust flow rate from the processing container 70b. A warning is output. Further, although many deposits 78 are adhered in the exhaust flow path 72 between the processing vessel 70b and the introduction port 76 where the air introduction path 73 is connected to the exhaust flow path 72, the air introduction path 73 and the flow rate are reduced. There are almost no deposits on the total 74. Further, as in FIG. 8, the adhering matter does not adhere to the exhaust passage 72 near the introduction port 76 and the exhaust passage 72 on the exhaust system side of the introduction port 76.

  On the other hand, as a comparative example, referring to FIG. 10 and FIG. 11, the introduction port is not provided in the middle of the exhaust passage, the air introduction passage is not connected via the introduction port, and the flow meter is provided on the exhaust passage. Think about the case. 10 and 11, the exhaust flow path is 172, the flow meter is 174, the monitoring unit is 175, the monitoring unit body is 175a, the alarm output unit is 175b, and the deposit is 178.

  FIG. 10 shows a state in which the exhaust passage 172 has not been operated after the maintenance process of the exhaust passage 172, and almost no deposits are attached in the exhaust passage 172. FIG. The exhaust flow rate of the exhaust flow path 172 at this time is QRN. At this time, the magnitude relationship between the value QRN sent from the flow meter 174 to the monitoring unit 175 and the predetermined lower limit reference value QALM is determined. Since QRN> QALM, the monitoring unit 175 does not output an alarm. Further, no deposits are attached to the flow meter 174.

  FIG. 11 shows a state in which a small amount of deposit 178 is adhered in the exhaust flow path 172 after performing the maintenance process and performing a little operation as compared with FIG. The exhaust flow rate of the exhaust flow path 172 at this time is QRA. At this time, the magnitude relationship between the value QRA sent from the flow meter 174 to the monitoring unit 175 and the predetermined reference value QALM is determined. Since QRA <QALM, the monitoring unit 175 outputs an alarm. As shown in FIG. 11, in the portion where the diameter of the exhaust flow path 172 in the vicinity of the flow meter 174 is narrowed, the narrow flow path is originally almost closed, but between the processing vessel 70 b and the flow meter 174. In the exhaust flow path 172, the deposit 178 is not so much adhered yet. Therefore, although the deposit 178 has not yet adhered to the exhaust flow path 172, the deposit must be removed and washed in the flow meter 174 portion, and the maintenance cycle cannot be lengthened.

  On the other hand, in the heat treatment apparatus according to the present embodiment, the exhaust from the inside of the processing container does not pass through the flowmeter whose flow path is narrowed down, and adhering matter does not adhere near the flowmeter. In addition, the maintenance cycle for determining the monitoring range of the flow rate by the flow meter (the above-described allowable variation range of Q1) is not the operation time until the adhered matter adheres to the narrow part of the flow meter and the piping is blocked, but the exhaust time This is determined by the operation time until the deposit adheres to the inside of the pipe of the flow path 72 and the pipe is blocked. Further, the diameter of the exhaust passage 72 can be made larger than the diameter of the flow meter. Therefore, the maintenance cycle in the present embodiment can be made longer than the maintenance cycle in the heat treatment apparatus in the comparative example, and the maintenance cycle can be extended even when the allowable fluctuation range of the exhaust flow rate is set small. . Further, in the present embodiment, the exhaust flow rate can be stabilized because the fluctuation range of the exhaust flow rate when the operation time is equal is small.

  Here, the maintenance cycle can be lengthened as the diameter of the exhaust passage 72 is increased. However, in order to monitor the flow rate of the air introduction path 73 with an appropriate amount of exhaust gas flow rate, it is desirable to reduce the diameter of the exhaust flow path 72 to some extent.

  Specifically, when Q0 is set to 30 L / min, the diameter of the exhaust passage 72 can be set to 15 to 25 mmφ, and the diameter of the narrow portion of the flowmeter 74 can be set to 10 to 15 mmφ. Further, when Q0 is set to 5 L / min, the diameter of the exhaust passage 72 can be set to 3/8 inch φ, and the diameter of the narrow portion of the flow meter 74 can be set to 2 mmφ.

When Q0 is 30 L / min, QN1 = 20 L / min (QN2 = 10 L / min), QA1 = 14 L / min (QA2 = 16 L / min), QALM = 15 L / min (QALM ′ = 15 L / min) min).
(Second Embodiment)
Next, with reference to FIG.12 and FIG.13, the heat processing apparatus which concerns on 2nd Embodiment is demonstrated.

  First, the heat treatment apparatus will be described with reference to FIG. FIG. 12 is a schematic front view showing the heat treatment apparatus according to the present embodiment. In the following text, the same reference numerals are given to the parts described above, and the description may be omitted (the same applies to the following modifications).

  The heat treatment apparatus according to the present embodiment has a heating unit and a blow gas supply unit for removing deposits adhering to the inside of the exhaust channel and cleaning the inside of the exhaust channel, and a collecting unit is provided. This is different from the heat treatment apparatus according to the first embodiment.

  The heat treatment apparatus according to the present embodiment is also the same as the first embodiment in that it can be applied to the heat treatment apparatus in the resist coating and developing treatment system. Further, the hot plate 70, the processing container 70b, the air introduction path 73, the flow meter 74, and the monitoring unit 75 are the same as those in the first embodiment.

  On the other hand, in the present embodiment, a heating unit 81 and a blow gas supply unit 82 are provided on the exhaust flow path 72a, and a collection unit 83 is provided on the exhaust system side from the heating unit 81.

  The heating unit 81 is provided between the processing container 70b and the introduction port 76, and heats the piping of the exhaust passage 72a in order to make it difficult for deposits to adhere to the inside of the piping of the exhaust passage 72a. Moreover, the heating part 81 can also heat and vaporize the deposit | attachment, when a deposit | attachment adheres inside the piping of the exhaust flow path 72a.

  The heating unit 81 is provided on the exhaust passage 72a between the processing container 70b and the introduction port 76 where the atmospheric introduction passage 73 is connected to the exhaust passage 72a. There is no limitation on the heating method as long as it is possible to make it difficult for deposits to adhere to the inside of the pipe of the exhaust passage 72a. For example, a heating mechanism such as a heater provided inside or outside the piping of the exhaust passage 72a may be provided to heat the piping from inside or outside. Alternatively, a heat anchor or the like for conducting heat from the processing vessel 70b to the piping of the exhaust passage 72a may be provided, and the heat generated by the hot plate 70 may be used.

  When the heat generated by the hot plate 70 is used, the exhaust flow path 72a is configured to have a double pipe structure including the inner pipe 72b and the outer pipe 72c in order to efficiently use the heat, and the processing is performed. The atmosphere in the container 70b may be exhausted through the inner pipe 72b, a heat anchor from the processing container 70b may be attached to the inner pipe 72b or the outer pipe 72c, and the inner pipe 72b may be kept warm by the outer pipe 72c. Further, a vacuum heat insulating structure may be provided between the inner tube 72b and the outer tube 72c, whereby the heating effect for further heating the inner tube 72b can be enhanced. In FIG. 12, the outer tube 72 c also serves as the warming portion 81 because the outer tube 72 c heats and keeps the inner tube 72 b. In addition, the heating part 81 may be provided in the exhaust system side rather than the inlet 76 on the exhaust flow path 72a.

  By providing the heating unit 81, it is possible to make it difficult for deposits to adhere to the inside of the exhaust passage 72a. Therefore, the maintenance cycle can be lengthened.

  The blow gas supply unit 82 includes a blow gas nozzle 82a that blows blow gas into the exhaust passage 72a, and a blow gas supply source 82b that supplies the blow gas to the blow nozzle. The blow gas nozzle 82a supplies the blow gas to the inside of the exhaust passage 72a in the portion where the heating unit 81 is provided, or to the inside of the exhaust passage 72a in the portion on the processing container 70b side of the heating unit 81. Provided. The blow gas nozzle 82a supplies blow gas to the inside of the piping of the exhaust passage 72a, and blows and cleans the deposits heated and vaporized by the heating unit 81.

An inert gas such as N ₂ gas can be used as the blow gas. Further, in order to prevent the vaporized deposits from reattaching to the inner wall of the pipe of the exhaust flow path 72a, a heating mechanism may be provided in the blow gas supply source 82b, and the blow gas may be heated before being supplied.
By providing the blow gas supply part 82, the deposits inside the piping of the exhaust passage 72a are blown and washed. Moreover, since the component of the deposit | attachment in exhaust_gas | exhaustion is diluted with blow gas, it can prevent reattaching in the exhaust flow path 72a. Therefore, the maintenance cycle can be lengthened.

  The collection unit 83 is a so-called cooling trap that is provided closer to the exhaust system than the heating unit 81 and collects the components in the exhaust by cooling and solidifying. The collection unit 83 may be provided on the exhaust system side with respect to the heating unit 81 on the exhaust flow path 72a. The collection unit 83 is provided outside the heat treatment apparatus and further outside the resist coating and developing treatment system 1 and connected to the exhaust system. It may be provided to be included. As shown in FIG. 12, the collection unit 83 has a collection plate 83a provided in a stacked manner, and the collection plate 83a itself or a cooling gas supply unit 84 provided separately from the collection plate 83a. Thus, the exhaust from the processing container 70b is cooled, and the solidified component in the cooled exhaust is cooled. The solidified component in the cooled exhaust gas is collected by solidifying and reattaching to the collection plate 83a or the inner wall of the collection unit 83.

  When the gas passing through the collection plate 83a itself is cooled, a cooling element is provided on the collection plate 83a, and the collection plate 83a is cooled by conduction cooling from the cooling element. As the cooling element, for example, a Peltier element or the like can be used.

  When cooling the gas passing by the cooling gas, a cooling gas supply unit 84 is provided in the collection unit 83, and the cooled cooling gas is supplied into the collection unit 83. The cooling gas supply unit 84 includes a cooling gas nozzle 84a that ejects the cooling gas into the collection unit 83, and a cooling gas supply source 84b that supplies the cooling gas to the cooling gas nozzle 84a.

  By providing the collection unit 83, the deposit in the exhaust channel 72a is vaporized by the heating unit 81, and the component of the deposit that is exhausted in the exhaust channel 72a blown and washed by the blow gas supply unit 82 is It is not discharged to the outside of the heat treatment apparatus, that is, the exhaust system side such as the factory exhaust system. Therefore, it can be prevented from adhering to the outside of the heat treatment apparatus, that is, in the piping such as the exhaust duct on the exhaust system side.

  In the present embodiment, by using the heating unit 81, the blow gas supply unit 82, and the collection unit 83 in combination with the flow meter 74 and the monitoring unit 75, the maintenance process can be automated. Hereinafter, the maintenance process according to the present embodiment will be described with reference to FIG. FIG. 13 is a flowchart for explaining the procedure of each process of the maintenance process of the heat treatment apparatus according to the present embodiment.

  The maintenance process according to the present embodiment includes a process for supplying blow gas (step S21), a process for measuring Q2 (step S22), a process for sending Q2 to the monitoring unit 75 (step S23), and subtracting Q2 from Q0. It includes a step of estimating Q1 (step S24), a step of determining whether Q2 is smaller than the lower limit reference value (step S25), and a step of stopping alarm output (step S26).

  Note that the normal method of monitoring the exhaust flow rate before performing the maintenance method according to the present embodiment can be performed in the same manner as the method described with reference to FIG. 6 in the first embodiment.

  After outputting an alarm and stopping the operation of the heat treatment apparatus, step S21 is first performed. In step S21, the blow gas for blow-cleaning the deposits is supplied to the inside of the pipe of the exhaust passage 72a while the exhaust passage 72a is heated.

  Next, step S22 is performed. In step S <b> 22, the exhaust flow rate of the air introduction path 73 is measured by the flow meter 74.

  Next, step S23 is performed. In step S <b> 23, the measured value of the measured exhaust flow rate Q <b> 2 of the atmosphere introduction path 73 is sent to the monitoring unit 75.

  Next, step S24 is performed. In step S24, the sum Q0 (= Q1 + Q2) of the exhaust flow rate Q1 from the inside of the processing container 70b and the exhaust flow rate Q2 of the atmosphere introduction path 73 is made substantially constant by the method described in the first embodiment, for example. By subtracting the measured value of Q2 from Q0, Q1 is calculated and Q1 is estimated.

  Next, step S25 is performed. In step S25, the lower limit reference value QSTD of Q2 is determined in advance, and the magnitude relationship between the predetermined lower limit reference value QSTD and the measured value of Q2 is determined. Specifically, it is determined whether Q2 is smaller than QSTD. If Q2 is larger than QSTD, the process returns to step S22 again, and the processes from step S22 to step S25 are repeated. On the other hand, if Q2 is smaller than QSTD, the process proceeds to step S26.

  In step S25, the upper limit reference value QSTD 'of Q1 may be determined in advance, and the magnitude relationship between the predetermined upper limit reference value QSTD' and the estimated value of Q1 may be determined. In this case, specifically, it is determined whether Q1 is larger than QSTD '. If Q1 is smaller than QSTD', the process returns to step S22 again. On the other hand, if Q1 is greater than QSTD ', the process proceeds to step S26.

  In step S26, when Q2 is smaller than QSTD, or when Q1 is larger than QSTD ', it is determined that the exhaust flow rate from the inside of the processing vessel 70b has returned to normal, and the alarm output is stopped. The alarm output from the alarm output unit 75b of the monitoring unit 75 is stopped, the operation of the heat treatment apparatus is restarted, and the normal exhaust gas flow rate monitoring method described with reference to FIG. 6 in the first embodiment is performed.

  Further, the above-described maintenance process is not limited to the case where an alarm is output and the heat treatment apparatus is stopped. For example, a reference value QREF smaller than the upper limit reference value QALM of Q2 that outputs an alarm is determined in advance. In addition, while performing a normal exhaust gas flow rate monitoring method, when it is determined that Q2 is larger than QREF, the maintenance process may be performed simultaneously while operating the heat treatment apparatus. In addition, when another cleaning dummy process (cleaning dummy sequence) different from the maintenance process for cleaning the exhaust flow path 72a is prepared and the substrate is being processed by the hot plate 70 of the heat processing apparatus, another cleaning process is performed. The maintenance process may be performed in synchronization with the dummy sequence.

As described above, according to the present embodiment, in addition to performing a normal exhaust gas flow rate monitoring method, it is possible to automatically perform a maintenance process for cleaning deposits adhering to the exhaust flow rate pipe. The maintenance cycle can be increased.
(First Modification of Second Embodiment)
Next, with reference to FIG. 14, the heat processing apparatus which concerns on the 1st modification of 2nd Embodiment is demonstrated. FIG. 14 is a schematic front view showing a heat treatment apparatus according to this modification.

  The heat treatment apparatus according to this modification is different from the heat treatment apparatus according to the second embodiment in that it does not have a collection unit.

  The heat treatment apparatus according to this modification is the same as that of the second embodiment in that it can be applied to the heat treatment apparatus in the resist coating and developing treatment system 1. Further, the hot plate 70, the processing container 70b, the air introduction path 73, the flow meter 74, the monitoring unit 75, the heating unit 81, and the blow gas supply unit 82 are the same as those in the second embodiment.

  On the other hand, in this modified example, since the collection part is not provided, the component of the deposit that is blow-cleaned by the blow gas supply part 82 and exhausted in the exhaust flow path 72a is not collected by the collection part. . In this case, the deposit may be removed by an exclusion device such as a scrubber provided outside the resist coating and developing treatment system 1.

Further, in this modification, the heating part can make it difficult for deposits to adhere to the inside of the exhaust passage pipe, and the blow gas supply part blow-cleans the deposits in the exhaust path. The air is exhausted without reattaching in the vicinity. Therefore, the maintenance cycle can be lengthened.
(Second modification of the second embodiment)
Next, with reference to FIG. 15, the heat processing apparatus which concerns on the 2nd modification of 2nd Embodiment is demonstrated. FIG. 15 is a schematic front view showing a heat treatment apparatus according to this modification.

  The heat treatment apparatus according to this modification is different from the heat treatment apparatus according to the second embodiment in that it does not have a blow gas supply unit and a collection unit.

  The heat treatment apparatus according to this modification is the same as that of the second embodiment in that it can be applied to the heat treatment apparatus in the resist coating and developing treatment system 1. The hot plate 70, the processing container 70b, the air introduction path 73, the flow meter 74, the monitoring unit 75, and the heating unit 81 are the same as those in the second embodiment.

  On the other hand, in this modified example, the blower gas supply unit is not provided on the exhaust passage 72a, and the collection unit is not provided on the factory exhaust system side of the exhaust duct 66. The components of the kimono are not blow-washed by the blow gas supply unit, and are not collected by the collection unit when the exhaust passage 72a is exhausted thereafter.

  However, as in the first modification of the second embodiment, if the deposit component can be removed by an excluding device such as a scrubber provided outside the resist coating and developing treatment system 1, It is not necessary to provide a collection part. Moreover, if the sum Q0 of Q1 and Q2 can be increased, the components of the deposits vaporized by the heating section do not re-adhere in the exhaust flow path without performing blow cleaning. The exhaust system can be exhausted. Therefore, also in this modification, the maintenance cycle can be lengthened.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to such specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. Can be modified or changed.

  The present invention can be applied not only to a coating film forming apparatus or a resist coating and developing apparatus, but also to a substrate cleaning apparatus, a film forming apparatus, an etching apparatus, and other various apparatuses. In addition, the present invention can be applied to an apparatus including a step of transporting a semiconductor substrate, a glass substrate, and other various substrates.

65 Main exhaust port 66 Exhaust duct 70 Heat plate 70b Processing vessel 72, 72a, 172 Exhaust flow channel 73 Atmospheric introduction channel 74, 174 Flowmeter 75, 175 Monitoring unit 76 Inlet port 77 Inlet port 81 Heating unit 82 Blow gas supply unit 83 Collection unit 84 Cooling gas supply unit

Claims (9)

In a heat treatment apparatus that places a substrate having a coating film formed on the surface of the substrate on a hot plate and performs heat treatment,
A processing container for storing the hot plate;
An exhaust passage for connecting the processing container and an exhaust system for exhausting the atmosphere in the processing container;
An air introduction path for introducing air into the exhaust flow path through an inlet provided in the middle of the exhaust flow path;
A flow meter provided on the atmosphere introduction path,
A heat treatment apparatus characterized by estimating an exhaust flow rate from the inside of the processing container by measuring an exhaust flow rate of the atmosphere introduction path.   The heat treatment apparatus according to claim 1, wherein a sum of an exhaust flow rate from the inside of the processing container and an exhaust flow rate of the atmosphere introduction path is substantially constant. A monitoring unit for monitoring the exhaust flow rate from the inside of the processing container based on the exhaust flow rate of the atmosphere introduction path;
The monitoring unit determines a magnitude relationship between a flow rate value measured by the flow meter and a predetermined upper limit reference value, and outputs an alarm when the flow rate value is larger than the upper limit reference value. The heat processing apparatus of Claim 1 or Claim 2.   4. The heat treatment apparatus according to claim 1, further comprising: a blow gas supply unit that supplies blow gas for blow-cleaning deposits attached to the inside of the exhaust passage to the inside of the exhaust passage. 5.   The heat treatment apparatus according to any one of claims 1 to 4, further comprising a heating unit that is provided between the processing container and the introduction port and heats the exhaust passage.   The heat treatment apparatus according to claim 5, wherein the heating unit uses heat generated by the hot platen.   The heat treatment apparatus according to claim 5 or 6, wherein the exhaust passage has a double-pipe structure in the vicinity of the heating unit.   8. A collecting unit that cools the exhaust from the processing container and collects a solidified component in the exhaust is provided on the exhaust system side of the heating unit. The heat processing apparatus in any one of.   The heat treatment apparatus according to claim 8, wherein the cooled gas is supplied into the collection unit.

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